What engine could be used that fits the space of the stock engine?

re used to be a guy on the forum who put a flat six engine from a BMW motorcycle under a Daihatsu Atrai two wheel drive. Said it would go like stink.

If you aren’t concerned about clearance for the transfer case and front driveshaft swapping in an engine gets lots easier.

 

Yeah that’s all good but I would want to keep it 4x4 because that’s one of the most important parts of having a hijet climber